6 THE NAUTILUS. 



" desidiosa Say. Winnipeg. Also by Christy. 

 " humilis Say. Winnipeg. Also by Christy and Dawson. 

 Physa heterostropha Say. On all the lists. Quite uncommon here. 

 " ampidlacea Gould.? (Dawson.) 



" ancillaria Say. Lake of the Woods (Dawson). Also rarely 

 at Winnipeg. 



Aplexa lypnorum L. On all lists. Usually a fine shell here. 

 Planorbis corpiilentus Say. Lake of the Woods (Dawson). 

 " trirohis Say. On all the lists. 



" tnacrostowus Whiteaves. Lake of the Woods (Dawson). 

 " bicarinafus Say. (Bell and Dawson.) 



campanula/us Say. Winnipeg, also by Bell and Dawson. 

 exacutus Say. Winnipeg, also by Christy, Dawson and 

 Holland. 



Planorbis albt/s Mull. (Holland and Taylor.) 

 " parvus Say. On all the lists. 



tnnbiUcatcllus Ckll. (umbilicatus J. W. Taylor.) Bran- 

 don (Christy, etc.). 



Planorbis cristatus L. A pair from this place, identified by Dr. 

 Sterki. 







Planorbula armigera Say. On all the lists. 

 Ancyhis paroUcJns Hald. (Christy & Dawson.) 

 " riviilaris Say. (Dawson.) 



NEW SOUTHEKN UNIOS. 



BY BERLIN II. WRIGHT. 



N. Harperi, sp. nov. 



Shell smooth, with slightly elevated growth lines, bhick towards 

 the umbos and tinged with red towards the base. Shining above, 

 rayless, oblique or very inequilateral. Umbos elevated and nicely 

 rounded; substance of the shell moderately thick, thinner posteriorly; 

 bluntly pointed behind with an inclination to biangulation. Dorsum 

 slightly arched, ligament red, basal margin slightly curved ; nmbonal 

 ridge rounded above and decidedly flattened out at the posterior ex- 

 tremity ; teeth double in the left and single in the right valve, cardi- 

 nals pointed, compressed and oblique, with a supplemental tooth or 

 pointed callosity in the right valve midway between the cardinal and 



